Though 150 units seems like a lot, in Marathon games it definitely isn't. Even at only 2 units/turn/resource tile, it doesn't take all that long to get them full... FOR EVERYBODY. At which point strategic resources become nearly worthless because _nobody_ needs to trade for them. You may need some a bit further along, but if there's already 150 units there, there is absolutely no point in trading for more. And EVERYBODY is in that same boat. NOBODY needs more horses. NOBODY needs more iron. Etc.The only time that anybody needs a resource is just when a civ acquired the tech that revealed a "new" resource. And as far as I've seen, the civs _know_ that soon there will be a zero Demand for that resource, so in trading, they offer only ridiculously low prices for those resources. (One gp for 10, 20, 30 units of Iron?) Usually they also demand Favor to sweeten the deal in their favor. (Unintentional pun.) Putting that 150 ceiling on resource storage really killed Trading.