like everyone here i’m a liteon fan.
however i’m finding it difficult to find a vendor/seller of a reasonably priced liteon with HDMI
such as the DD-A510.
any ideas?

Wallmart or Fry’s depending on where you live. Ordering from LiteOnIt.com direct if you are in the outskirts.

Since LiteON have pretty much exited the DVD recorder market availability in many markets has dried up, though some markets where they did well are still going.