Not where I am looking - you can still get your hands on a t620 Plus as long as you can source a 3rd party HP notebook barrel adapter that can push out 90w on the cheap. As for the t730? Eh, there are some deals if you look carefully, but honestly, as a t730 owner, that machine really is getting a bit long in the tooth. I would not spend more than 220 USD on one.Alternatives? Its getting out of stock and the T730 is a bit pricey
Replacements? Depends on what you need to do with it. If you need the PCIe slot, you can probably find some bargains on an HP EliteDesk 705 G2 to G4 SFF business desktops. The G2s are about as powerful as the t730 but with more expandability, and the G4s can take the current generation Ryzen 2000s with a CPU swap (The G3s can do the first generation Ryzen 1000s). If you want simply a small cheap powerful NUC alternative, the 705G4 Minis are small Ryzen based machines. The G4 Minis are also strange birds in that HP made a discrete Radeon RX560 graphics card for it that can use the built-in MXM slot. They are fairly viable medium gamer NUCs as long as you hustle well and get a decent deal out of them. I am not sure if you can "break out" the MXM slot into an external PCIe x16 slot via a riser...would be fun if you can, but I doubt it.