I actually finished this game on 4/12/2011 but I haven't really remembered to post about it. I picked up Monopoly for WP7 when it was on deal of the week. For 2.99 it wasn't too horrible. Much better than the 4.99 I would have paid. In fact, I actually had been putting this game off purchase wise because of the price.
It was an easy 200G and only took me about 3 hours. The only achievement that I had any issue with was rolling 3 sets of triples. It is more about luck than anything else. You can get all of these achievements by playing a single game with 2 human players it doesn't matter which human player gains the achievement it will still pop on whoever's account is attached to the phone.
So all in all, this game is a quick and easy 200G and was well worth the 2.99 price tag. For 4.99 it will have to depend on how much you happen to like Monopoly.