How long can you keep them? If you are going to return the reel, don't forget about adding the cost of line. I suppose you could just swap it to another reel but it gets to be a hassle. If you are using FC, it'll cost you $7 or more to spool up assuming you do it yourself. A lot cheaper if you using mono.
Now if you are going on fishing vacation and want to have another premium combo for the trip, this sounds like a good idea. If you use it to your advantage, it is almost like you are renting a rod or reel. Interesting idea.