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
I agree with the answer above on test first. Also, David's advice to have a business strategy is key.
I'd start from user needs. Do people need (ok, want) this service in the area you might provide it? As a woman and a cosmetics designer, I can attest that most women want this service, but you need to check the following: Is the climate warm enough to sustain your business though the year? If not, what do you do in winter/off time? Think about diversifying your offer. Since this is a localized service, how about HHI (household income) in your town/city? For those within a middle income bracket, this kind of procedure is a luxury service.
Finally, if you're to really stand out among competitors, user experience should be your primary concern. For something as personal as laser hair removal, you will build your business on referrals (personal and digital via review sites like Yelp). Make sure every visit is impeccable. If you'd like to talk more, I'd be happy to dig in with you on crafting the ideal experience.