Maybe I can kinda answer your question... I haven't figured out how much it would take to ugrade my relic club, but I know for a fact that I'm definitely not rich enough to seriously consider it, lol.  Here is Bombadil's response to an idea Bdogg had for his LS; he wanted to have people /random to be able to lot ALL coins for certain runs to help people get their relic faster (from the Spirit forum):

Your thought about having relic in 1 year? lol..... You do realize that say you never recruit another single person. 40 people in your shell ok? 52 weeks in a year right? 2 runs a week? a year of runs equals a max of 104 runs a year ok. Still followin? Say an average of 250 coins in a run. Ok sooo for Spharai's it takes 17,900 coins. With your 40 people each person will get to take all the coins about 10 times every 4 years. so 2500 coins every 4 years. Even if you where to buy 3/4th's of the coins. that would still leave you with 4475 coins to get through your way. so a good 7!!!! <seven> years of runs. Oh yeah and the other 13,425 even if you got an excelent deal and say prices never ever increase again and you can get for say 30k a coin you will only need to come up with 402,750,000 gil L O L!?

Your eye's are to big for your stomach Bdogg. Plain and simple. 99% of full relic upgrades come from people with either A. A good craft at 100 that can churn out mass profit. B People who duped gil back when it was possible to do so. C. People who do dynamis with there LS and LS gave them every coin from every run for a str8 6 months. SE Made relic's dam near imposible for the regular person to obtain. Why do you think I never allowed sponsorships and allowed each person to get coins so they could afford there RR items and med's and food and such.

In the end, Bdogg abandoned his idea.  So collecting a few coins here and there... really a drop in the ocean.  You either need to be completely serious about relic and really rich, or be in an LS that is willing to sponser a small minority of people upgrading, or take years and years to work on it extremely slowly (or all of the above). 

Edit: to clarify, Bdogg didn't abandon the idea on upgrading.  He just abandoned the idea of having people /random to take all the currency from a particular run.  There's obviously nothing stopping people from joining, getting lucky and taking millions worth in coins, and then leaving.  Especially if you saw some of the shady characters in his LS... so he just changed coins back to being randomly sorted. 

Owain wrote:

---

Okay. Sorry. I figured it was probably a stupid idea, but like I said -- I'm a newb, I don't really understand how all of this stuff works. Sorry.

---

It's not a stupid idea.  The relic weapons are really awesome, it's just that I don't think I could be motivated to stick with it for that long.  That's a whole lotta cooking that I'd have to do ~.~  But if you wanna go for it, good luck!  Just realize that it takes A LOT.