New to this, How ever no one else has commented and the name did strike me as pretty good.
It depends who you are selling it to (End user or DNer) and how much you want to keep it?
When googling this term "OTSL(dot)ca" comes up. It appears from there website that they just revamped there website about a month after you bought this Domain. So there is a possibility that they are becoming more web savvy or have been advised that it would be a good investment to grab generic terms directly specific to there company. In this case they may really want it and offshore resources are big business as I suspect you may already know.
Do you know if it is this company? (check IP address and use an IP locator looking for Canada in particular Alberta) Or is it from a web based email address.
In which case it may be worth contacting (OTSL) and seeing if they want it directly.
Now to try answer your question. I may be wildly off but if this was mine knowing OIL is big business and knowing there is probally others that may want it I would not let it sell for less than $1500 (in my own opinion)
If this was another DNer I guess it would be wholesale at mmm low to mid $XXX mark, but I'd probally hold on to it for a bit longer.
Hope this helps you. If nothing other than to get other get others suggesting not to listen to me (guys please pm if this is the case asadvice is always taken well)
Good Luck