all the sites i continue to promote have good retention at $24.95 - or i wouldn't promote them the 3 best retaining sites i've promoted are all over $19.95:

bfcollection - $29.99
dominanttvs.com - $29.95
myfirstsexteacher.com - $24.95

why not mirror your tour and let your webmasters choose whether they want to promote the site at $19.95 or $24.95?