Ensuring rent payment while inheriting tenants

[Jonny Abramson]

Hey there BP! Wife and are finally getting ready to pull the trigger and we're are looking at a two flat. One unit is vacant and the other is rented for $700 with their lease expiring in October. Market rent per unit is $1100-$1300. A couple of questions are coming to mind when thinking about this deal. 

First of all, are there any means of ensuring that the current tenant is, in fact, paying rent? The last thing I want to do is inherit a non paying tenant and be stuck with them. 

Secondly,  when it comes to raising the rent is there anything "wrong" with just raising the rent to market value when their lease expires? Assuming, of course, that I'm ok with the fact that they may decide to move on which would mean a little vacancy and clean up. It's a big gap to fill from $700 to $1100 on the low end. I understand that this is somewhat subjective. With our purchase price, the deal would allow for slightly under market rent so if they turn out to be awesome tenants I could "ease" them up to market value over the next two years. Just trying to feel out what the general consensus on this topic is.

Thanks in advance everybody!

Jonny