Im so sorry for the late response, but your email got lost in my inbox (unfortunately I get quite a few emails each day).

The different in magnification basically how many times larger the object will appear. (Not logarithmic like decibels or anything) so literally something that's 1mm will appear to be 1m if your magnification is 1000. So the difference between 1000 vs. 1400 a decent amount. That might be the major thing you're purchasing for as an amateur astronomer. But it's not like you'll be able to see something clearly in the higher magnification telescope, but not at all in the other (that happens if the telescopes differ in magnification by orders of magnitude). Is there anything that you're interested in looking at specifically? Like particular filters or anything? If you just want to examine stars and planets, then I would go for the telescope with higher magnification. I think at those magnifications planets will be quite interesting. I searched for the telescopes on eBay as you said, and I think I saw them but I couldn't be sure.

If you like, if you send me the links directly to the people selling them, I can make the inquiries =) but as long as both are in fine condition, the telescope with the larger magnification is probably the way to go.