Wanted to post a follow-up on this "inexpensive panels" thread...
I finally got around to installing the 500w system on my RV with two 250w panels. I'm happy to say that the SanTan used solar panels (~10yr old) are working beautifully and cranking out plenty of power.
Here's a good link to the install project:
https://www.rv.net/forum/index.cfm/fuseaction/thread/tid/30217540.cfm
I'll be adding a 3rd lead acid battery soon making my battery bank 300AH. Then, as a test I'll drain the batteries at night to 50% (-150AH) and I'll let you know how much the 500w system gets them back up to by the end of the next sunny day.
I liked this setup so much, I've decided to ditch the brand new 200w Windy Nation syetem and just install an identical 500w system (two 250w SantTan panels and a 30amp MPPT controller) onto my 2nd RV. If anyone lives in the CA Bay Area and wants a good deal on a brand new 200w Windy Nation system, feel free to send me a private message.
Happy Camping!
Chris