Should I invest 100,000 + in new business to make it look good and be professionally acceptable, or should I invest the minimum just to test the market but then I may get hit by bad reviews for my service. The Service I intend to offer is laser hair removal
Only go all if if you need to. (And chances are... you don't need to.)
I will say - from personal experience in offline service based businesses - you might be surprised at how little you need to invest to look "professionally acceptable".
This of course depends on your market and their expectations... However you might find that what YOU think is important to "look good" isn't important to them.
Remember that it's all about them. They don't know (or care) how much you invest in your business. They don't even care if you make any money. They care about what's important to THEM.
My advice is to have a plan (aka business strategy). In business you aren't investing if you have no plan... you are speculating - And that means you will be taking on much more risk than you need to.
And by the way... if you are providing amazing service then the reviews will be good ones.
Let me know if I can be of assistance. In any case I wish you the best of luck!