I did some quick looking, better time to get this type of thing is around some other major holidays, especially after Thanksgiving.
As of right now, this looks "ok" as far as specs. If you happen to have a Staples around that has it in stock. It's faster than others mentioned, more storage, more memory/RAM, etc. It is compact, if something like the power supply goes out after warranty, the actual full size towers are easier to get aftermarket stuff than this small one, but being an HP, shouldn't be difficult. I didn't look if it uses a standard size smaller one. Anyway, wouldn't worry about it. Also, if you pay with a credit card, many of them double the warranty free automatically up to a year additional. Like I said, HP not my favorite, but I wouldn't be scared of it or anything.
https://goo.gl/BjWSq4
Amazon currently has it, low stock, but $40 higher. I don't know where you are, some areas have the store "Microcenter", they have a refurbished one cheap, only 90 day warranty though.
http://www.microcenter.com/product/469429/slimline_260-p026_desktop_computer_refurbished
There's a different type of drive you can put in them to make them much faster, but probably not worth it for basic use. Cost $50+ depending on size, and they are going up now, speculating on market price manipulation. Just that, switch it with the other drive, then reinstall Windows etc.
Depending what kind of monitor you have, you may need to check the connectors. This has both major common types, there is one higher quality older one it doesn't have. New monitors are around $100 more or less for nice big ones.
Otherwise, Dell outlet sometimes has decent stuff. Their refurbished is "fine", never had issues, same as new warranty, sometimes even onsite (you contact, they send someone out, no shipping). They used to have coupon codes with big discounts, not as much anymore. Sale now, but not in the lower end stuff as much, at least that I saw in a quick glance. Their inventory changes all the time, until you complete checkout, someone else can even buy what's in your cart. You can order by phone too.
http://dell.com/outlet , click on desktops. You can refine the search, or sort by lowest price, and again I'd suggest something with at least "Processor: Intel Core 6th Generation i3-6100 Processor". The ones that are Celeron or plain Pentium will be slower. Their refurbished ~similar to the HP above new are close to the same price. Any I've dealt with from there have been as new though, unless you get a "Scratch and Dent", but often those have a small "dimple" or something, sometimes you can't see it.