I am considering the same issues. There will undoubtedly be wifi only Android tablets that are significantly cheaper. The Archos 101 is currently $300 - granted it is not of the same quality, but there are many others coming. The galaxy tab can be had for $499.
As for the iPad- the base model- no 3g - may be 200 cheaper, but put in comparable memory and 3g and the price is just as high as the Xoom.
The Notion Ink should be out at $425 for the 3g LCD model.
I simply think its not time yet- this summer will be the mark. By then we should see a plethora of competitive android tablets, the ipad 2, and most carriers on board. The early adopter costs should be gone by then as well once the competition of actually shipping devices heats up. Additionally we should see Gingerbread at leat and maybe even Honeycomb by then.
I think anything you by now would be simply a "test" device just to begin to assess the true viability of an android tablet as a netbook/laptop/e-reader replacement. It will allow you to explore possibilities of android in this form factor, but by summer it will likely be either outdated or, in the case of the Xoom, you will have paid a high price for early adoption.
Verizon Galaxy Nexus