Any success/advice for lightening hair slowly with 10 vol developer instead of once with 30-40?

Hello!
I started a discussion a while ago about wanting to bleach and color my own hair, and my original plan was to bleach once using 20 vol for around 45 minutes and then tone and color. But since then I’ve done more research and I don’t really think that’s the best idea.
I have level 4-5 natural brown hair, type 2 waves, and my hair is a bit past shoulder length and thick.
My goal is to have my hair level 8-9 by my senior ball so I can dye it purple to match my dress. Also I’m only doing the bottom half of my hair using balayage/babylights techniques. The purple dye I will be using is Arctic Fox and that’s curly girl friendly so I’m not worried about that part.
As you can probably guess, since it’s my senior year I don’t have a lot of money to get it done professionally, as I’m saving for college. I’d like to be able to do it myself using slow and spaced out processes, and I don’t want to lose the wave pattern I’ve worked so hard for.
So here’s what I’m thinking:
I’ve already been deep conditioning every single week, not using heat, only washing my hair twice a week, and using almost all CG products(I clarify my hair with a sulfate shampoo once a month). My goal is to get my hair as healthy as possible before I start bleaching.
My senior ball is the first week of June, so I’m thinking if I do one bleach process a month starting in February, it’ll slowly become the level I want. Correct me if I’m wrong, but I believe 10 vol mixed with bleach would lift one level each process, so since I have 4-5 hair now, when I bleach in February it’ll be a 5-6, March a 6-7, April a 7-8, May an 8-9.... you get the point.
I would also probably tone between processes so I’m not walking around with orange yellow hair until I’ve reached my desired level. Also, I may use the ion absolute perfection booster(olaplex dupe) to make the process even gentler.
If you can, please let me know if you’ve tried similar methods and give me feedback.
I started a discussion a while ago about wanting to bleach and color my own hair, and my original plan was to bleach once using 20 vol for around 45 minutes and then tone and color. But since then I’ve done more research and I don’t really think that’s the best idea.
I have level 4-5 natural brown hair, type 2 waves, and my hair is a bit past shoulder length and thick.
My goal is to have my hair level 8-9 by my senior ball so I can dye it purple to match my dress. Also I’m only doing the bottom half of my hair using balayage/babylights techniques. The purple dye I will be using is Arctic Fox and that’s curly girl friendly so I’m not worried about that part.
As you can probably guess, since it’s my senior year I don’t have a lot of money to get it done professionally, as I’m saving for college. I’d like to be able to do it myself using slow and spaced out processes, and I don’t want to lose the wave pattern I’ve worked so hard for.
So here’s what I’m thinking:
I’ve already been deep conditioning every single week, not using heat, only washing my hair twice a week, and using almost all CG products(I clarify my hair with a sulfate shampoo once a month). My goal is to get my hair as healthy as possible before I start bleaching.
My senior ball is the first week of June, so I’m thinking if I do one bleach process a month starting in February, it’ll slowly become the level I want. Correct me if I’m wrong, but I believe 10 vol mixed with bleach would lift one level each process, so since I have 4-5 hair now, when I bleach in February it’ll be a 5-6, March a 6-7, April a 7-8, May an 8-9.... you get the point.
I would also probably tone between processes so I’m not walking around with orange yellow hair until I’ve reached my desired level. Also, I may use the ion absolute perfection booster(olaplex dupe) to make the process even gentler.
If you can, please let me know if you’ve tried similar methods and give me feedback.

0
Comments
Keep in mind, that sometimes once with a high power developer is gentler than many times with a low. If you wanted, use the 20 volume first. Evaluate. Then use the 10 volume if it is 1.5-2 levels of your desired level once a month until you reach your desired level.
As for toning in between, just to let you know, that may not work out. Toner typically starts at level 8.
One last piece of advice, if you go to a salon (not a high end one... I don't know where you live but where I live you can find cheaper old school salons), you might end up with a cheaper expense when you compare it to buying supplies.
What you are wanting is not that difficult and shouldn't be too expensive, I would seriously check a hair school to see if you can get it done there.