Hmmm...Glenlivet 18 and Lagavulin 16 are what, $70 or $80 in WA? That's what I would consider an "average" priced single malt. Before you get into the the different oaks, take some time and really go region by region and explore the base flavors. I wish I had done this earlier.
Here's a recommended "hit list". Some of these I haven't tried, but come as highly recommended (and are on my list to try).
Oban 14 (highland)
Dalwhinnie 15 (highland)
Balvenie 12 Doublewood (Speyside)
Glenfarclas 15 (Speyside)
Macallan 18 (Speyside)
Highland Park 15 (Island)
Talisker 18 (Island)
Bunnahabhain 12 (Islay)...I wouldn't normally recommend another Islay as you've tried my normal 1st and 2nd choice with Lagavulin 16 and Laphroig 10, but Bunnahabhain is much more subtle.
Auchentoshan 12 (Lowland)
Springbank 15 (Cambeltown)...I NEED to try this one (have heard great things)
Work through that list and you'll see what awaits you down this road.
Average price for a single malt is around 50-60 bucks. That would be for a decent 12 year (e.g. MacAllan 12 or Balvenie 12).
I think the Oban is good, but like the similar (but better, IMO) Glengoyne 17. Oban also puts out a special release for a few dollars more that is quite tasty (Kimmo - they have it at the E Pine liquor story in Seattle, the last I checked).
Highland park 15 is excellent (and also still reasonably priced).