New clone vs used vanguard

I know this has been discussed to death but I feel like talking about some more since it's something I'm actively contemplating.

I have Yamaha G2. Currently had a little itty bitty Honda gx 240. I had planned to buy and build a 440 clone for next year. I'm in Canada so shipping is a killer and Canadian money is worth less than USD.

A new bare bones 440 clone would cost about 325 Canadian dollars. Then I would need a connecting rod ($170), push rods ($50), VC cam ($80), valve springs ($25) and probably rockers ($80?).

That's over $700 Canadian for a reliable 18-20 hp and 6000rpm.

Now, where I'm having trouble with this idea is that I keep seeing used 16hp vanguards for sale for about $350 Canadian. Assuming the vanguard isn't worn out, my understanding is that all it needs is a rev kit (valve springs and timing key?) to make 18-20hp and 6000rpm..

Assuming i can get a rev kit for a 16hp vanguard to my door for under $100 Canadian, I could have 18-20hp and full pressure lube for under $450 Canadian all in.

So ~$450 for the vanguard vs ~$750 for the clone.

The vanguard seems like a no brainer.

Does this all make sense?