We were in a very similar boat. Tried naturally for number two for a while, then figured we would need some help. Also had feelings about how far we wanted to go when we weren't pursuing parenthood, but adding to our family.
At your age (which is mine also) the doctors were very candid that anything other than IVF would be wasting our time and money. To me, IVF seemed like pulling out the big guns and I had a hard time getting my head around jumping right to that point, but I did appreciate the honesty of the clinicians that IUI and other methods were unlikely to produce results. We are with Shady Grove and they "assigned" several informative modules/videos for us on the various options, I found them helpful.
If you are even thinking that this is something you might want to pursue, I would start the process. It took quite a while to wait for a consult appointment and then a while to complete the baseline tests (some have to be done on certain days in your menstrual cycle so we often had to wait several weeks to begin). I used that time to get my head around the idea that we were going down this path - I am glad I was "multi-tasking" as if I would have waited until I was mentally ready, we would have lost a lot of time.