CYA with multiples of high price item

[ericlovescameras]

Hi. I am selling a expensive, discontinued, and fragile film stock. I can edit the listing so that it says there is more than one available. The thing is, I do not want any one buyer to buy more than two sets at a time. Every once and a while I have to close my eyes and jump with cameras that costs hundreds, but in this situation I can prevent a $500+ order by limiting the number in the listing. 

But I have heard there is an SEO advantage to having a listing where some of the stock has sold and some remains. Can I continue to edit the listing to add more as it sells? Or will that reset the available / remaining counter? What if someone buys all that's remaining? Then can I no longer add more with out creating a new listing?

Are all these questions in vain? Does it really help promote your listing or does it not matter? 

Thanks!

[wastingtime101]

You can enable the out of stock setting in your site preferences. That will keep the listing active for a few months when the quantity reaches zero so you can keep updating it as items sell.

You can also update your buyer Requirements in site preferences. There's a setting where you can limit the number of items a buyer can purchase within a certain timeframe. The only problem with that is buyers can use multiple accounts or check out as a guest to get around that block.

[ericlovescameras]

awesome! thanks. exactly what i was looking for. made both changes. one more question. my listings all count down from 30 days even though when i click revise listing, "Good 'Til Cancel" is the selected option in grey type indicating it cannot be changed. will the out of stock option still work?

i don't understand Good 'Til Cancelled. Sometimes all my listings say that next to time remaining, and then the next day they're all on a 30 day count down without explanation for the change.