@Madeline184 This is a tricky situation. On one hand, the owner is somewhat responsible for leaving expensive personal items in the home in which I assume is primarily a vocation rental. However, it is also the guest's responsibility to take basic safety measures and accountability to make sure the property is adequately cared for and safe during their stay.
That being said, you have a couple options.
1.You fully acknowledge the theft of the bike was the result of you leaving the garage open during your stay. Therefore, you can agree to cover the replacement cost and accept that you learned a valuable lesson.
2. You can try to come to an agreement on a price that is within your budget.
3. You can refuse to cover the cost and allow the host to decide what steps he would like to take moving forward. (I don't recommend this) Although I am familiar with aircover as a host, I am not sure if this situation would be covered by insurance. If not, he could result to taking legal action.
Lastly, I have an uncle who is an avid lifelong cycler. Bikes can easily be in the price range in which the host identified, so it's not too much of a stretch to think it may in fact have been worth 3k+. However, before agreeing to pay anything, as someone else suggested, Id ask for proof of the bikes value in the form of receipts or another form identifying the bikes make and model.
