To answer the OP, not now. Coming downstairs is really cheap. But the thing that got me back into cycling, after a gap of what must now I think about it have been something like 15 years (I'd been keen as a teen, then got into motorbikes, then gave them up on account of kids) was when my monthly travelcard went up to £120. For the next 15 years or so I saved £120+ a month, every month. I had to buy new tyres every now & again, the odd brake block, chain, cable. I did all my own maintenance. I bought new bikes (well, new old bikes, off
ebay) but always sold the old one, generally for what I'd paid for it, or more.
All in all, I'd say commuting by bike must have saved me somewhere a good way north of £20,000.
And I loved it. I really did. I miss it.