Yep, you got the plan down.

Couple other tips for the last 10 second tactic....

~open a 2nd window with the auction, so you can SEE the countdown timer AND your active screen.
Someone else could bid in that last few seconds and you NEED to see that action so you know how high you want/need to bid.

~Pre enter your bid amount and then stop at the screen with "Confirm bid"...that way all you have to do is hit "confirm bid" button.

~since this is the 1st time you're doing this, I'd suggest hitting the "Confirm" button at around 15 seconds.....in case your internet is a bit slow or something.
(But do take note of your internet connection function in the preceeding minutes...if it's slower than usual, hit "Confirm" earlier)

****IT's up to $101 right now....
Looking at the bidder list, I see it's somebody with (3) feedback that seems to be after it....Since often, the newer ebayers don't understand this system...you can see that (3) has entered numerous stairstep bids...Probably doesn't understand the proxy system...

I think you should go a tad higher than $120....if you can afford it.....
Based on his pattern, I think (3) doesn't have a very high max bid entered...so I'm optimistic for you.