Really? Tell me when you hit Team level 67. Let me be clear. By then, you have plenty un-used fragments, in short, sell it as you go when you don't need them.
You will need about 2 Teams, that is 10 Heroes to clear crusade. I'm not exactly sure how you are going to get the gold for all the things you need. BEAR IN MIND, 10 HEROES. At those level, you are considering to max their skills. Purple gear least 2 or 3 Star enchanted. Now that's only Gold, another issue you will face when you are around that level, is your EXP Potions.
At about that level, you can only level few heroes per day your core team.
So what is my Point? You will not having enough resources to keep up your hero level and skill if you are going to have plenty Heroes. Then? Why not sell Heroes Shards that you don't need? Like keeping it will do any good for you. It doesn't help on advancing your Heroes.
What you said on EXP is correct, What i have been saying is selling Heroes Shard that is not on your core team. Its unnecessary to hold them either way. If you want to collect all heroes then feel free to do so. But as you progress from the start, if you know you are not going to use the Heroes, simply sell it. Either way you are contradicting yourself. Read the sentence I quoted and bold.
To both of you, let's not forget about this thread. It's "How to raise money" -- Feel free to disagree, but hey, when you reach 60++ you will have plenty un-used gear & reel fragments and also Not Your Core Team Heroes Shards sitting idly on your inventory. Some of the items from lower level wont be used as often so you will have plenty of spare. Sell it when you actually need the cash to power up your core team to compensate the lack of gold income.