If I buy clothing in bulk from a supplier and use a 3PL, is it still realistic to sell them within the $10-$20 range?
You need to spreadsheet it. Cost of purchase Cost of delivery Cost of sales What % do you buy but have to dump? What net profit do you need? If you fail can you afford the loss? Who is your target market? Do they buy fashion online? How long will a garment remain fashionable to your market? What is their preferred price range? Is low cost considered "cheap and nasty" or just "fast fashion" that they're happy to bin after a few wears?
I am not sure. Ive had my eyes on a few but so far I have just been hearing horror stories about all of them.
Asking about a price range for a product without any information about what type of product it is (as @mmerlinn points out) and without indicating what market(s) you plan to promote the product in (one of the points made by @sarahk) is not going to get you good answers. And, unfortunately, you have a much bigger issue to consider, anyway: There are more online and offline clothing vendors of all sorts and sizes than can be counted. They offer everything from new, to used, to rentals, and more. To say that this is a mature, saturated market is an understatement. So, the big question is: Why will anyone buy from you, instead of the myriad, well-known and trusted sites that have been out there for years?
Not so fast, for months now I have been searching in vain for a clothing line that will offer clothes that will match my assortment of tinfoil hats. You think that I can find even one?......no!
I think that clothing designers around the world are intimidated by the advanced design, style, and grandeur of our tinfoil hat collection.
In short, yes it is realistic. But you need to do the marketing right. There are plenty streetwear and skatewear brands that sell very basic designs for upwards of $100 just for a shirt! People are happy to pay an arm and leg for brand names these days.
Without seeing your entire business plan, it sounds like a lot to risk, for what sounds like alot of hassle. Not my niche, so I cant say for sure if you should go for it or not. I will say that there are multiple websites and companies where you can send them your own custom patterns, set up like a basic shop or links to your products. They sell their clothes, with your designs, ship, handle payments, and you get the profits. No outlay, (other then the time (or money) spent on design and graphics). To me, its a better risk vs reward.