Based solely on second hand information, I'd suggest the Samsung 2233RZ. 120 HZ (which appears to be more than just a marketing gimmick), 22 inch (a little under) and it runs about $330. Of course don't take my word for it, but TFTCentral uses it as their new reference monitor (they even compare it to the IPS monitors) and if you read through their reviews/basic information, they have an idea of what they are doing.
The review is here (and it contains a nice run down on why 120HZ is more than just for 3D video)
http://www.tftcentral.co.uk/reviews/samsung_2233rz.htmThe lowest cost is from Dell at $300 (assume another $30 or so for taxes)
http://accessories.us.dell.com/sna/prod ... u=A2910141This is a normal TFT Film panel (not IPS as with the 2410U) and so input lag and response time appear to be top notch, while colour representation will be no where near the 2410U but from the review, appears to be quite decent. IPS monitors (such as the 2410U) are not the end all, be all of high quality monitors; they are just a preference of many who require/want the higher colour gamut and honestly, the magical, mystical qualities of IPS panels are sometimes exaggerated. If anything, poke around tftcentral.co.uk because they also have guides on the different types of panels (PVA, TFT Film, IPS) and general all around information in regards to monitors.