You probably should look at the sticky at the top of this forum and fill out the survey questions in a new post.
But - HGVC is not a great value used in RCI for trading (almost always). You'd be better getting a cheap / free RCI trader - probably like at Grandview in Las Vegas that's regularly being given away, or available cheap cheap cheap. The MFs on a week stay in a 2BR at Grandview tend to be around $950 I think, and HGVC after club fees etc seem to often be more like $1,500. That said, having HGVC for their locations, and using the RCI membership to buy Extra Vacations and Last Calls can be a huge benefit IMO. Not everywhere has cash offers in RCI, but at least for me, places like Massanutten, Smugglers Notch, Williamsburg, Myrtle Beach, Hilton Head, Ft. Lauderdale and Orlando very often do if you're not super picky about location and extremely specific dates.
A "quadruple play" many here suggest would be buying one or more of the Craig Lodges Scotland deeds and enrolling it with HGVC so you get HGVC and RCI automatically, adding to DEX and also using it to get an II membership. This will get you many many options each year as well as many cash deals - at the cost of paying an additional II membership fee, and only being able to use each owned week as a week in RCI, II and Dex but getting the flexibility of 3 day stays on years you use in HGVC - but each week can only be used in one of the systems each year.
Will you save vs Expedia? If you can use timeshares "correctly" per the TUG methods - again read and answer the survey and more of TUG - then almost certainly yes. However the amount of savings can vary wildly from like $100 to $3,000 or more on a given week depending on the location and dates and method of booking.