Information about Martin Logan Sequel II

Just purchased a pair of these for $250 but have option to return within 10 days if I choose. A couple of questions - when hooked up at store, high frequency driver did not work on one speaker - is this likely a driver out (and expensive to fix) or a problem in the built in amp that may be more economical to fix? Also, assuming they can be made whole for hundred and a half or so, are they worth repairing or are they prone to certain issues that I should be aware of? I am narrowing my choice of speakers down to: these when repaired, Paradigm studio 80s, Snell EIIIs, and a pair of Alon Model IVs (that I recently upgraded and restored) I have not compared these yet as the Alons require a great deal of power to properly evaluate (so I have been told) I have acquired an Adcom 5800 but have not rigged it for bi-wiring yet. Anyway, any opinions on this would help me decide about investing a little more on the Martin Logans or cut my losses and take them back. Thanks, Jon.