So, I got an email today from Gforce Software where they have released a new Reason Rack Extension (Chambertron) for $25.  They've also lowered their two other products (Re-tron and Re-strings) to $49 each. 
 
Since Gforce Software is pretty expensive (and doesn't regularly go on sale), what do you think of this idea to get the sounds for cheaper:
1. Buy Reason Essentials (which allows for RE's) for $60 at JRR shop
2. Buy the 3 rack extensions ($124)
3. Use Reason via Rewire to use the sounds.
 
That puts the total investment at $184 for quite a big chunk of their sounds.  
 
Is this a dumb idea, good idea, or somewhere in between?

is there any crossgrade path to the VSTs? the only thing with you plan is you can only use them via reason, and you may end up spending unexpected time fiddling with reason itself
the VSTs do come up on kvr very occasionally, but licenses go nfr after the first resale

I don't see any info about a crossgrade path unfortunately.

Gforce software usually has a sale at least once a year. Get on their mailing list so you'll get a notice. 

I do receive the emails.  The problem is that Gforce actually doesn't have regular sales.  The last major sale on their main products (as best I can tell) was back in 2014.  Each product got a week with 50% off.
 
They've had some sales on the expansions for M-tron since then, but not on their main line of products (Oddity, Imposcar, M-tron, VSM, etc).
 
They don't even do a black friday or Christmas sale

I do like their RE versions quite a bit, although I also have some VST ones.
The RE's (I have RE-Tron and RE-Strings) are easy to use but, true, you need Reason (Essentials). Version 10 is being launched, so you'll enjoy the latest.
Thinking about getting the Chambertron RE myself, as $25 is cheap. Then again, it's available as a cheapish VST expansion too.