As someone who likes to play with trading power and availability in both II and has owned 2 gold Barony Beach weeks, 1 platinum manor club, and one EOY Marriott Willow Ridge, but have either sold, had one taken back by ROFR, and sold two back to Marriott (they weren't offering brokered resales for any of my units at the time when I was divesting them) I know the meaning and value of Marriott preference.
That said the OP started off by saying he wanted to explore II and thought Marriott would be a good choice. I feel unless you have a specific plan for exchanging into Marriott units where the preference is needed that Marriott is too expensive to use as a trader in II. I kept my WR to use to exchange into gold season at Hilton Head until earlier this year. I found I could exchange into Harbor Club for the week I needed without preference and could possibly eplus into one of the big 3's some of the time. My family decided the $300 or so in savings for the week was worth it. We really don't like Myrtle Beach or HHI in the summer. Haven't made it down to any of the Florida resorts and the Orlando ones are still exchangable without Marriott. Manor Club is an easy exchange with almost anything. So for us there just wasn't any value in having a Marriott exchanger. I still have them in my II account so I can still play with the the value for instant exchange.
For me it wasn't an expensive lesson. I probably made about $1000-2000 total over what I paid and I enjoyed the experiment.
My take on WR which is one of the more cost effective exchanges. You are looking at about $1100 in MF plus the lock off fee. The 1 br exchanges very well. I would value that at about $750 of the $1100. The studio is very mehh. Even valuing it at $350 may be high. Even though it has Marriott preference it just couldn't pull most 2 br that I needed. It would occasionally perform great but I attribute that more to II glitches because sometime something that was available with the studio would not show a few days later even though it was still sitting in inventory and I would log off and refresh or even try to match by setting up an ongoing request (which I would cancel if matched). To me the studio was like a bonus week but still not the most economical bonus week.