Absolutely agree with that advise. I have UPS’s on all main systems (and on my home theater equipment).
As for the battery prices, I’ll agree as well, but I think they do that just to keep sales up. However, you can usually find battery replacements at local battery warehouses. You just need to call them up or visit the store with the battery so they can cross reference the numbers.
I’ve been enjoying CyberPower UPS’s lately. I purchased a few TrippLite UPS’s that were horrible. If you want a decent UPS for around $100, take a look at this one: http://www.newegg.com/Product/Product.aspx?Item=N82E16842102132
Actually, Amazon has it cheaper, but the shipping cost may be higher: http://www.amazon.com/gp/product/B00429N192/ref=olp_product_details?ie=UTF8&me=&seller=