Since you appreciate the value of listening, but don't want to shop around at the brick and mortar stores, I would recommend buying from online vendor with a generous return policy. Recently I ordered a couple pairs of outdoor speakers, listened to both sets for a few weeks, chose one set, and returned the other at the cost of $7 - no questions asked.
They offer quite a good selection, maybe a little pricier than the competition, but sometimes have lower sale prices.
Obviously there are a great many good bookshelf speakers that cost under $500. I like the PSB speaker brand because they are fairly mellow, yet rich with detail. Though not as efficient as some brands and a little power hungry. The PSB Image.
Though above your price range, currently selling for $599, the Polk Audio Lsi9 speaker is fantastic. The speaker uses two 5.25 inch drivers for midwoofer and woofer duties. Very strong and dynamic bass. A one inch ring radiator delivers ultra-clear, shimmering high frequencies. They play like a tower speaker with the dual woofer arrangement and very deep, ported cabinet. A very well tuned speaker for rock music that sold for $800 before the newest Polk models were recently released - the LsiM series.
They are big and power hungry, but your Emotiva amp will have no problem.