It has been awhile since I was Gold - so this could have changed - but I do not remember
always getting upgraded at that level???? If I am going to pay for something, I want to insure I am going to get it!
Silver only takes 10 nights; most CL's are not open on the weekend; and resorts and other properties (RI, CY, SHS, etc) do not even have one. When you take that into consideration, I am not sure that the expenditure is worth it. I am also not sure which hotels you are looking at where an upgrade is $200+ - I don't recall ever seeing that.
Since it appears that you will be spending SOME nights, you shouldn't be more than a few short of maintaining Silver. I would just check for MEB,M11, or other specials that bring the rates down (usually on a weekend) and "pay" to maintain silver status that way.
If you are "jealous" of your points, (understandable

); then you also need to insure that you are maximizing your earning potential whenever possible through the extra promotions MR offers....
ex: I am currently in a FS on a MeB rate of $99 per. I have a BB for $100; so 2 nights will cost me $99 - but I will earn an extra 5K points for being in a FS on the weekend, due to a promotion that is currently being run. So I am basically earning 7000 or so points for an expenditure of $128. ($99 + tax).
SO - if you were to do the same thing - you could do it twice (roughly) would earn 4 nights towards Silver status, AND gain 14,000 points rather than spending any for the $200 + points you are proposing to spend.
In another post, a guy is at a CY for $59 - has a $50 BB - so is spending 2 nights for $9 +tax - - - with a free breakfast thrown in.
Just a thought............