Have you also considered Bay Lake Tower? Also on the monorail, has studios (standard, lake, and theme park view), 1 bedrooms, 2 bedrooms, and grand villas. Walking path to the MK. Expiration is 2060 (versus Poly 2066 and BCV 2042).
Maintenance fees are lower than Poly ($5.92 versus $6.20 per point).
Points go further there than Poly, as well:
Poly studio Magic season: 169 points (standard) or 199 points (lake view)
BLT same period: 139 points (standard), 153 points (lake view), or 183 points (theme park view).
In any case, 100 points is likely to be your "starter" purchase. After a short while, you'll get "addonitis" and add another block of points to stay longer or in larger accommodations.