Some good advice but a few too many "definitives".
There are clothing lines that don't use screen printing. Transfers across the board don't equate to poor quality or the perception of such. Just like screen printing doesn't mean "high quality". There are tons of contributing factors. There's growing trend towards "soft hand/waterbase" feel. But I see many vinyl type applied images that are wildly popular and fashion-priced. Special effect printing using gels, HD, suedes, glitters/shimmers, rhinestones, foils, discharge and various combinations. And custom photo transfers using dark paper on both light and dark fabrics because some folk like the heavier shinier finish and at $30-$40. As far as production capabilities, it too depends on where you are as far as quantities needed, pricing, market, exclusivity etc.
As far as samples, bloggers/magazines will perceive whatever quality you present. Not just the garment but you, your business/logo/promotional imaging etc.
And screen printing isn't across the board "hard". It can be messy but doesn't have to be. And a "lot of space" is relative. There are "spare room" setups that make money and a lot of quality product.
There are TONS of different transfer types, decorating/embellishment processes out there that appeal to myriad clientele and they all have the potential to be "poor quality". Do some serious woodsheddin' and research the gamut and decide which one(s) you have an affinity for, find or create a market, work out the details of pricing, production, sales, image etc and of course think big!