Seems quite expensive, but nice to know
The ostrich (30d) is on promo from time to time, every 4 weeks, so you could have it forever on discount if you buy in time...
so is there anything i am missing?
Most custom rings (from Dalanis Nightmare, ROFL red and ROFL golden) give you another 35%(?) movement speed for 10 mins that overwrites the yellow housemaid potion, but 35% is better than 15% I guess
There are Golden Wings that give another approx 10% move speed passively and grant a short-time buff of +50% for 10 seconds with like 60s CD or something. But golden wings are quite expensive, but just telling fyi
There are some useful titles available within some instances, 10% move speed from DL Normal mode or some events, 15% from ROFL chests after b2...
The fancy Boots (shown in Screenshots of Daenerys ) can only be used inside of instances (as shown in their tooltip) but only in most custom instances, such as ROFL, Gorge, DC and nostalgia. You cannot use them in vanilla instances and iirc they won't work in tikal as well
However, the 30d ostrich does work in Tikal (and Inferno afaik) plus all vanilla instances and outside of instances in the open world and even inside player houses, but not in nostalgia or other custom instances. So if you don't run custom content excessively yet, you may prefer the ostrich in the first place
This being said, there is just one fact left to mention: Movement speed is multiplicative, so you wanna stack as much as possible, so you reach that "godlike" speed you mentioned
EDIT: If you are warlock, you additionally have 2 interesting ISS, one from Sardo Castle NM (lv 67), called "Self-Distortion" that gives 30% speed while costing HP every second and one from Crypt of Eternity (lv 90), called "Path of Anguish" that adds 50% for 10 seconds. Some other classes got additional speed buffs, such as Warrior/Rogue got a passive of like 30% or something, etc. Maybe this might be useful for you as well