Is this answer spam or is it acceptable?
I think offering services would be OK, IFF the company makes a solid attempt to answer the question first, and makes an offer for their services for additional help or a more comprehensive solution as an addendum or something at the end of their answer.
This one didn't attempt to address the question at all, so I'm inclined to lean toward the spam view on it. (As for the links, I didn't think 1-rep users could add links...) An answer that detailed the many ways the import may be difficult, some of the later things that are likely to crop up, etc. would also have made me view the pitch for services in a better light... after all, it may be that the best solution really is "pay me to fix this for you".
Do you think your reaction be any different if they had a higher rep score?
Say they had 10k rep., their answer would be more like "We've done this before, we had to do ABC then DEF but don't do XYZ or it will blow up. Contact us if you get stuck"
As it stands, until they change their attitude, their answers aren't going to get upvoted.
I don't think there is much you can do to prevent this. It's quite easy to setup an rss feed on a tag.
The fact that they had +1 tells me they won't be around for long...