  We consider budget feasible mechanisms for procurement auctions with additive
valuation functions. For the divisible case, where agents can be allocated
fractionally, there exists an optimal mechanism with approximation guarantee
$e/(e-1)$ under the small bidder assumption. We study the divisible case
without the small bidder assumption, but assume that the true costs of the
agents are bounded by the budget. This setting lends itself to modeling
economic situations in which the goods represent time and the agents' true
costs are not necessarily small compared to the budget. Non-trivially, we give
a mechanism with an approximation guarantee of 2.62, improving the result of 3
for the indivisible case. Additionally, we give a lower bound on the
approximation guarantee of 1.25. We then study the problem in more competitive
markets and assume that the agents' value over cost efficiencies are bounded by
some $\theta \ge 1$. For $\theta \le 2$, we give a mechanism with an
approximation guarantee of 2 and a lower bound of 1.18. Both results can be
extended to settings with different agent types with a linear capped valuation
function for each type. Finally, if each agent type has a concave valuation, we
give a mechanism for which the approximation guarantee grows linearly with the
number of agent types.
