I buy a lot on line also,including furniture.Have bought furniture from 2 diff private sellers this yr.
1st was a sewing cabinet/table I bought & was pleased with.Next was my "buy of the year",a Sleep Number bed.That trip was worth every mile.The bed was right size,like new...one yr old.barely used & being sold by ppl downsizing.Price was 1/4th the cost of new & he even gave me his receipt.
Done buying furn...we have a small house & don't need a thing.I did my homework,shopping retail prices,looking on line & in stores.Then I get pics from sellers,then a ph number where we can talk to them,asking lots of questions.My offer to buy is "only if" the item is as described,when I see it.
For on line fabrics, I add the sale price to shipping & sales tax (if applied) against retail price/tax at LQS.Don't figure gas because the LQS & Joanns are within a couple blocks of where I do my grocery shopping.These days,we all have to use our money as best we can. Works for me.