If Arsenal are not willing to let him go as a way of exchange, then is it possible for Arsenal to buy him without any exchange. Because, if Arsenal can afford to buy Declan Rice then of course a player swap doesn't have to happen either but yes, after all West Ham still has to have great players because to play in the Europa League as well next season. It's also interesting to look forward to because after all, Declan Rice is also the team captain which of course West Ham won't be easy to let go of and of course will be priced at a high price.
So good to see incredible transfer this summer, gunners making big moves for their ultimate priority players. They place bid for Declan Rice. After winning the European Conference League, Westham will lose one of their most key players this summer. David Moyes will bring in a capable backup midfielder to replace Declan Rice. This is the first transaction that I'm thrilled with; Arsenal should strive relentlessly to sign Declan Rice, who is a key player on their transfer rader. He will provide sophisticated contributions to the midfield, filling the void left by Granit Xhaka.
I think, with the current conditions, sooner or later the conditions regarding Rice will definitely be at Arsenal. The chances are very high in this case even though the price is not cheap but it is not a big problem for them especially as you said, this could be a good replacement in the position left by Xhaka.
Rice has always been a target for Arsenal more than ever although this is a bit late but now is a good opportunity to bring in this player and I wouldn't be too surprised if in the next few weeks this is confirmed to be a done deal.