Parks shipping for seeds is reasonable, too. But I mostly only buy seeds, not plants, from them. Although I have been tempted by their calibrachoa.
To be clear, my complaint with Summer Hill dates from a co-op back on DG several years ago. Many of the seeds I got did not germinate, the quantity in the seed packs was meager, and the prices, even in a co-op, were on the high side. And they did NOT respond to my complaints. Maybe things have changed since then, tho. Other people seem to think well of them.