Steering rack question

I have a 2001 Nissan Avenir W11, with about 230,000k on the clock. The car goes very well, so I would like to keep it a while longer, but there is a small leak from under the large end of the LH steering rack boot. There is just a film of oil on the end of the rack around the boot, nothing dripping (yet). Obviously ther must be a leak in the end seal of the rack, if there is fluid inside the boot. My question is, can such seals be replaced, or is a completely overhauled rack required? Likely cost? I guess it's a matter of how much is worth spending on an old car.

check if it has axial play . and what colour the power steering fluid is. most use atf dexron like the hilux and my mb140 van and your nissan also with 95% gurantee. it is a nice redwine colour. you would purge clean fluid as first step.
Then to the hilux i done seal by auckland rebuild place . upon removal i noticed both side where gone = full rebuild it was 1200 bux removal rebuild and refit as it had failed the wof .
polaris place east tamaki auckland i paid to rebuild rack. between lockdowns last year
http://www.nz-hotrod.com/vbulletin/printthread.php?t=4680

Thanks for that, I did have the figure of $1200 in mind form somewhere. At what stage does it fail the WOF? So far there is minimal fluid loss, just dropped a couple of mm in the last 6 months. Yes, the fluid is Dexron3, it says so on the reservoir cap.

exessive play or obvious leak is the fail but more play as you could mask a leak with a sponge lol.