This is the interesting question. It gets very much into the gestalt of how we try to understand what the Russian intentions are. There are the arguments that Putin is doing this, of course, simply for domestic consumption to show that he is the strong man. In other words, there is this whole aspect that he's not even focusing on the outside world.
However, the issue of course is why in 2007 they had maintained this at substantial cost and, of course, whether they are going to follow through with the new advanced bomber as they say they are. If they don't, many of the premises of your question are, indeed, in order.
The second part of your question is whether we actually need the F-35. Theoretically, could we have a cheaper aircraft, something that perhaps will provide us with the type of air superiority or at least air surveillance that fighters give us? The answer is in theory yes, but we simply don't see that type of company capability.
As I said, the Eurofighter is probably going to come up at a cost roughly akin to what the F-35s are, or at least that's the speculation. That may be proven to be wrong, but it's an older technology, and it won't last quite up to the 2060 timeframe. I expect we'll be seeing the F-35s go...despite the government saying they will be replacing them sooner.
If you're not willing to go to the Russians to buy your fighters, there really are going to be limited options. You either go with the F-35, which may not be a perfect fit, or you go with nothing. It's almost the type of choice that any government...and this was reflected, of course, even with the Liberals when the initial contract in the mid 1990s to engage in the development of the F-35 was taken. This is the real challenge any western government outside of the United States is going to be facing.