I wouldn’t recommend buying from overseas, you’ll be left with no warranty. At least if you buy here, you can kick the tires on the saw and you have the initial part of the warranty, at least until you leave the country.
The sales tax thing is becoming hit or miss as online retailers are moving to collect tax in all 50 states. Amazon and CPO are charging tax.
The best deal I’ve found lately is monitoring eBay for their limited time coupons for 10-15% off. They just did one two days ago, so it may be weeks or months before you see another. Hartville Hardware in Ohio sells on eBay and I’ve been buying from them on and off eBay for over 5 years and have found them to be very good. They even list the package deals on eBay with dust extractors or MFT (I think), so you can also get the 10% Festool savings.
Other good smaller retailers are Bob Marino and Toolnut (festoolproducts.com). I don’t know where they stand with tax collection at this time, but both are a pleasure to deal with. Acmetools is also very good to deal with, but don’t order items indicated as backordered. Their boilerplate message indicated the warehouse is acquiring the product in 7-10 days is not always true. I can confirm as of a few weeks ago they aren’t collecting tax yet.