In 2017 a 2 BR GB usage fee was ~$1500 and a 2 BR GM was ~$1400, depending on when the owner bought in. The resort fee does get the relative costs close to a wash between the two ways of getting there. I'd say it winds up being a personal choice for folks as to whether it's worth it.
If it's a 2 BR Grand Luxxe, possibly (IMO) as i know the MF they quoted me at the sales presentation was approx. $1800 for a 2 BR GL.
for GM/GB, seems excessive, but I guess it depends.
With HGVC, it's 4800 points to get into a 2 BR GM/GB. Depending on what type of unit one bought with HGVC, that could be about $800 in MF (or more, but I'm going with mine which are cheaper).
Plus the $240 RCI Exchange Fee.
Plus the now, $30/adult (let's assume 4 adults) = 840
So: $800 + 240 + 840 = 1880. (edited) forgot to add in the $11/adult/day RCI fee, so another $308), brings it up to: $2188.
More than the GL MF (and a lot more than the GM MF if I recall as they kept wanting me to buy so they downgraded, etc.)
Average rental on Redweek for 2 BR GM during similar season (just for comparison) is about $1700-$1800.
Currently I can pick up 2 BR GM/GB via SFX for a cost of $702 plus the $75/unit charge, so let's just say $800 with my exchange. GL is $300 more.
As always, your mileage may vary. I think that's the highest charge I've seen lately on exchanges ($30/adult/day) for a non-AI resort. I know DVC is starting something like a $25/day/unit charge and some HGVC via RCI exchanges are around the same (but it's not per adult, AFAIK).
Given the wash between exchanging and renting direct from an owner, (in most cases) I'd say rent from an owner so you get the actual benefits (well mostly, depends on what their contract says) as sometimes you get a free spa or round of golf.