As someone who is required to wear tartan hose when wearing a kilt, I feel your pain in regards to the price of such hose. Especially when you have a youngster that tends to grow out of the things fast.
As an experienced tartan hose wearer I can tell you that they don't wear out as quick as you think. Wool tends to felt up first. Granted, a dancer doesn't wash their socks as often as they should, but if you wear a sock liner neither will you.
Knitted hose are easy to repair. Holes can be darned (ask for extra wool when you purchase your hose for darning purposes).
And, I know plenty of dance parents who've sent their child's hose away to have new feet or toes knitted in when their child's feet have gotten too big for the foot of the hose. If your darned soles are in need of renewing this option could work for you.
There's two well known hose makers that dancers frequent, both of which enjoy an excellent reputation. In fact, I know the local well-known kilt maker here in NS orders all their hose from either of these companies, but marks up their price double.
http://www.kilkeelknitwear.com/
(don't be fooled by the 'Tartan Dance Hose' tab, this section has a very interesting lecture on the knitting process and pictures show that they'll make adult non-dance hose)
http://www.familytraits.co.uk/socks_page.html
(don't let the dull web page fool you, many, many people love their Henderson Hose)
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