Well that depends if you want to play with all the Factions right off the bat. I am not a big fan of the DLC age we have had thrust upon us, but by no means do I feel forced to buy any of the DLC for either of these games. I bought the DLCs I wanted for the first game and didn't bother with others with Factions I weren't interested in, like the my old friendgy Wood Elves. Even Attila is still knocking on toward £90 I think for the game and all the DLCs and I don't think Rome 2 is far behind.
The four factions that come with the game have plenty of play time within them due to their uniqueness and the 'core' of the game made the first game worth its price without the DLC content. My biggest gripe is that I don't feel WH2 justified another £40 price tag, because the core of the game is just WH1, on a different map, with different artwork and different factions. So I felt like I was paying for the core of the same game again, just reskinned, so less value for money, would have been nice if they offered a decent discount for owners of the first game, like £30 would've been nice at least. I did think to myself "But only 4 factions, compared to all the older games many more factions!", but when I thought about it reasonably, each of these Factions in WH1 and WH2 TW, are unique and require MUCH more work to create than those in any of the older titles, where everyone was human and most Factions had plenty of cut and paste units.
If you bought both the WH TW games before or around release date to receive the early buyer bonuses, but didn't buy any DLC, you will still have access to I think 10 Factions/Races in Mortal Empires. Correct me if I am wrong, but I remember that there were 4 playable in WH1 ( Empire, Dwarf, Greenskin, Vampire ), with Chaos as a bonus for early buyer, making 5. Then 4 in WH2 ( High Elves, Dark Elves, Lizardmen, Skaven ), but with Norsca DLC for WH1 as a bonus, which might not be useful for WH2 right now, but they will be playable in Mortal Empires, making another 5. That's 10 different Factions without any DLC, 10 factions that are much more unique than any Faction in any other TW title, each with their own unique faction mechanics and Rosters etc. But not just 10 Factions/Races, you also get multiple Legendary Lords to play as, which can change the way you start and how you play the game, at least in WH2 the Legendary Lords make a big difference in starting a game and how you might play it. If you didn't get them around the release dates, you still have what, 8 Factions and their respective Legendary Lords, some of which make a noticeable difference.
All in all, yes it is fairly expensive if you want the Mortal Empires business, but you don't need to buy the DLC straight away and can justify the purchase of DLC over time if you are actually playing enough of what the core game offered already. And in my opinion, compared to older TW titles, it actually is better value for money, touching on what I mentioned earlier about the Factions and Races being far more unique and differing in gameplay. And at least on Steam you can buy both WH1 and WH2 (without DLCs ofc), for as cheap, or cheaper, than you can buy Attila TW and all its DLCs, or Rome 2 and all its DLCs, which both contain a ton of cut and pasted units with no where near the variety of campaign and gameplay mechanics for the differing Factions even with all their DLCs.
Is it worth it? if you're a TW fan then yes, I believe it is, especially if you are a TW and a Warhammer fan. Though the game does have some bugs and issues atm, but any TW fan knows that's how all TW games are released
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