Frodo had it lucky. For him the One Ring only cost him a finger. For rocketeers, one ring can cost an arm and a leg.
Let’s suppose you need a centering ring to go from BT-50 to BT-55. Just one, or more precisely, one more than you have in your stash. You have a few options. You can get one from your club’s parts stash, if you have a club and they have a parts stash. You can get one from a friend, if you have a friend and they have a stash. You can get one from your local hobby shop’s huge inventory of rocket parts, if you have a local hobby shop and they have a huge inventory of rocket parts. But let’s assume for discussion you can’t or choose not to use any of those means. Instead, you’re going to go shopping online.
You could go on eBay, for instance, and find seller shopjonrocket selling individual centering rings at $0.99 each. Of course to that you have to add postage, which in this case, at least for shipping to upstate New York, is $3.60, so that’s $4.59 for one centering ring.
Or you could go to jonrocket.com, where presumably the same centering ring goes for $0.20 each — but the shipping is $8.95! That’s $9.15 for one ring.
At Rocketarium you can’t buy one centering ring. You can buy a package of six for $5.45, plus $5.95 shipping. $11.40 for the transaction, but it comes to only $1.90 per ring. Which isn’t much consolation if you will only ever in your lifetime need one BT-50 to -55 ring, but seriously, if you make more than a few scratch builds a year, you’ll use six up before too long, so if you can come up with the $11.40 now, you’ll be better off later.
(The Rocketarium rings are plywood. The Jonrocket ones are fiber. For this exercise I’m assuming you don’t care, you just want whatever’s available at the best price. Also the Jonrocket rings come with a moist towelette, but again, I’m not taking that into consideration.)
The variation in shipping rates gets pretty nuts — especially when you consider that, if it’s thin enough, you can stick a single centering ring (or a few) into an envelope, slap on one forever stamp, and send it like that. Arguably there’s some benefit to the seller in setting a rate like $8.95: it encourages the buyer to buy more. If you can get a centering ring plus a couple of kits for the same shipping cost as one centering ring, your build pile is likelier to be looking kind of thin. And generally speaking, of course, if you can combine your purchases so you’re not getting just one or a few centering rings shipped, it’s better for everyone. Sometimes, though, you really don’t need anything but a few small parts, and then the shipping cost bites you. The extreme examples I’ve found are Belleville Hobby and Heavenly Hobbies, which charge $17.49 and $16.99, respectively, for shipping; Heavenly Hobbies also charges tax which apparently is figured on the order total including shipping. You can buy two centering rings from Belleville for $1.74 but after shipping they’re $9.62 each!
If you really want just one centering ring at the lowest possible cost, the best deal I’ve found is eRockets; they’ll sell you two, not one, but the shipping cost is low enough to bring the total below anyone that’ll sell you just one, though shopjonrocket on eBay comes close. Here are the amounts you’d pay at nine vendors to get the smallest possible number of rings sent. (Note: I’m not sure about Apogee: what they’ll sell you is cards containing two centering rings, “quantity 4” — it isn’t clear if that’s four rings or four cards, eight rings. I’ve assumed the former.)
|Seller||Lowest cost||Number of rings|
|Uncle Mike’s Rocket Shack||$10.50||10|
If you want to minimize cost per ring, though, by buying up to twelve rings and throwing the extras in your stash, eRockets again does best, with Jonrocket (from their web site) second and Uncle Mike’s a close third. (Uncle Mike’s is kind of hit and miss on parts, though; in fact, at the moment, BT-50 to -55 seems to be the only centering rings they have!):
|Uncle Mike’s Rocket Shack||$1.05|
Really the moral to the story is, plan your purchases so you don’t have to do anything as dumb as placing an order as small as this through the mail. I try to. Sometimes successfully.